As unions have come under fire in states across the country, the differences in opinion between how Republicans and Democrats view organized labor have grown to historic margins, a new poll shows.

Republicans and Democrats have diverged dramatically in their views toward unions over the last year. This year’s Gallup poll on labor unions, released Thursday, shows that the gap between Republicans and Democrats on labor union approval is 52 percent, up from 37 percent last year.

Overall, only 26 percent of Republicans approve of unions, compared to 78 percent of Democrats. Last year, 34 percent of Republicans approved of unions, compared to 71 percent of Democrats.

Meanwhile, overall disapproval of labor unions remains near historic highs. A slim majority of Americans — 52 percent — approve of unions, up from a record low of 48 percent in 2009, while 42 percent of Americans disapprove of labor unions, according to Gallup. Historically the difference has been as low as 25 percent.

Gallup’s annual polling on labor unions shows that their support has fallen from a high of 75 percent in the 1950s.

Labor unions were brought to the forefront of public attention earlier this year when Wisconsin Gov. Scott Walker challenged Democrats and public-sector unions over collective bargaining rights. In February, Walker proposed that government workers would lose collective bargaining rights on issues other than wages.

Just weeks ago, the public outcry led to nine recall elections that resulted in two Republicans being voted out of office.

The partisan split on unions was interpreted differently by union and anti-union organizations.

“The divide reflects the fact that organized labor is more political than ever,” said Patrick Semmens, a spokesperson for the anti-union Right to Work Legal Defense Foundation. “Where once unions focused on the workplace, their focus now is politics - they get to play politics with the dues they force workers to pay. Unions have basically thrown in their lot with the Democrats. The fact that people are forced to subsidize their politics… it certainly offends people, in general.”

“Clearly, the need for a voice on the job is not a political issue, which is why there are many union members who are Republicans and why historical support of unions has not been based on partisanship,” said Alison Omens, Director of Media Outreach for the AFL-CIO, the largest federation of unions in the country. “As voters see that the people demonizing unions are the same ones pushing an extreme agenda… we expect voters to see those attacks are also dishonest.”

The Gallup poll on public opinions toward union was conducted from Aug. 11-14. This survey involved 1,008 adults, and its margin of error is plus/minus 3 percent.